91775403720 has 1536 divisors, whose sum is σ = 432042024960. Its totient is φ = 16257024000.

The previous prime is 91775403701. The next prime is 91775403761. The reversal of 91775403720 is 2730457719.

91775403720 is a `hidden beast` number, since 9 + 1 + 77 + 540 + 37 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 434954415 + ... + 434954625.

It is an arithmetic number, because the mean of its divisors is an integer number (281277360).

Almost surely, 2^91775403720 is an apocalyptic number.

91775403720 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91775403720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216021012480).

91775403720 is an abundant number, since it is smaller than the sum of its proper divisors (340266621240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91775403720 is a wasteful number, since it uses less digits than its factorization.

91775403720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 347 (or 340 counting only the distinct ones).

The product of its (nonzero) digits is 370440, while the sum is 45.

The spelling of 91775403720 in words is "ninety-one billion, seven hundred seventy-five million, four hundred three thousand, seven hundred twenty".